Cellular communications technology, including radio access technology, has grown rapidly and evolved since the launch of analog cellular systems in the 1980s, starting from the First Generation (1G) in 1980s, Second Generation (2G) in 1990s, Third Generation (3G) in 2000s, and Fourth Generation (4G) in 2010s (including Long Term Evolution (LTE) and variants of LTE).
Internet Protocol Security (IPsec) is a protocol suite for secure Internet Protocol (IP) communications that authenticates and encrypts each IP packet of a communication session, and can include integrity protection as well as confidentiality protection. Voice over LTE (VoLTE) service employs the use of IPsec confidentiality protection on the SIP signaling between the user equipment (UE) (e.g., smartphone) and a mobile provider's (e.g., AT&T's) IP Multimedia Subsystem, also known as IP Multimedia Core Network Subsystem (IMS) Core. The IMS core is an architectural framework for delivering IP multimedia services, and includes an S8 home-routed (S8HR) architecture for VoLTE roaming, which was introduced in 2017. In the S8HR architecture, which is a recognized architecture for VoLTE Roaming by Groupe Spéciale Mobile Association (GSMA) and is used in many parts of the world, the P-CSCF is in the home network of the wireless user (e.g., the user's user equipment). In the case of an international roaming UE that uses S8HR to make and receive VoLTE calls, the session initiated protocol (SIP) message is encrypted from the UE in country “X” to the P-CSCF in the United States. An attempt to perform a lawful intercept by governmental agencies in country X would fail to provide the call details in the SIP messages because the SIP messages would be encrypted everywhere across the visited LTE network in country X.
However, this encryption violates legal requirements in certain countries where the government demands that lawful interception of cellular voice be provided without encryption, such that the government would be able to access details of the message. The solution currently documented in 3GPP standards requires the home network provider to disable IPSec Confidentiality Protection when a customer is using VoLTE service with the S8HR roaming architecture. This allows the visited LTE network provider to intercept the SIP messages in clear text form and provide the call details to its Government agencies. The problem is that this 3GPP solution exposes AT&T and its VoLTE roamers to security and fraud risks when they are outside of the United States. It also puts the VoLTE service at a disadvantage to “Over-the-Top” (OTT) voice over IP (VoIP) applications that are free to use IPsec or other methods that provide security to callers.
The above-described background relating to wireless networks is merely intended to provide a contextual overview of some current issues and is not intended to be exhaustive. Other contextual information may become further apparent upon review of the following detailed description.